/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if 0
#ifndef lint
static const char sccsid[] = "@(#)termstat.c 8.2 (Berkeley) 5/30/95";
#endif
#endif
#include
__FBSDID("$FreeBSD: src/contrib/telnet/telnetd/termstat.c,v 1.13 2004/07/28 05:37:18 kan Exp $");
#include "telnetd.h"
#ifdef ENCRYPTION
#include
#endif
/*
* local variables
*/
int def_tspeed = -1, def_rspeed = -1;
#ifdef TIOCSWINSZ
int def_row = 0, def_col = 0;
#endif
#ifdef LINEMODE
static int _terminit = 0;
#endif /* LINEMODE */
#ifdef LINEMODE
/*
* localstat
*
* This function handles all management of linemode.
*
* Linemode allows the client to do the local editing of data
* and send only complete lines to the server. Linemode state is
* based on the state of the pty driver. If the pty is set for
* external processing, then we can use linemode. Further, if we
* can use real linemode, then we can look at the edit control bits
* in the pty to determine what editing the client should do.
*
* Linemode support uses the following state flags to keep track of
* current and desired linemode state.
* alwayslinemode : true if -l was specified on the telnetd
* command line. It means to have linemode on as much as
* possible.
*
* lmodetype: signifies whether the client can
* handle real linemode, or if use of kludgeomatic linemode
* is preferred. It will be set to one of the following:
* REAL_LINEMODE : use linemode option
* NO_KLUDGE : don't initiate kludge linemode.
* KLUDGE_LINEMODE : use kludge linemode
* NO_LINEMODE : client is ignorant of linemode
*
* linemode, uselinemode : linemode is true if linemode
* is currently on, uselinemode is the state that we wish
* to be in. If another function wishes to turn linemode
* on or off, it sets or clears uselinemode.
*
* editmode, useeditmode : like linemode/uselinemode, but
* these contain the edit mode states (edit and trapsig).
*
* The state variables correspond to some of the state information
* in the pty.
* linemode:
* In real linemode, this corresponds to whether the pty
* expects external processing of incoming data.
* In kludge linemode, this more closely corresponds to the
* whether normal processing is on or not. (ICANON in
* system V, or COOKED mode in BSD.)
* If the -l option was specified (alwayslinemode), then
* an attempt is made to force external processing on at
* all times.
*
* The following heuristics are applied to determine linemode
* handling within the server.
* 1) Early on in starting up the server, an attempt is made
* to negotiate the linemode option. If this succeeds
* then lmodetype is set to REAL_LINEMODE and all linemode
* processing occurs in the context of the linemode option.
* 2) If the attempt to negotiate the linemode option failed,
* and the "-k" (don't initiate kludge linemode) isn't set,
* then we try to use kludge linemode. We test for this
* capability by sending "do Timing Mark". If a positive
* response comes back, then we assume that the client
* understands kludge linemode (ech!) and the
* lmodetype flag is set to KLUDGE_LINEMODE.
* 3) Otherwise, linemode is not supported at all and
* lmodetype remains set to NO_LINEMODE (which happens
* to be 0 for convenience).
* 4) At any time a command arrives that implies a higher
* state of linemode support in the client, we move to that
* linemode support.
*
* A short explanation of kludge linemode is in order here.
* 1) The heuristic to determine support for kludge linemode
* is to send a do timing mark. We assume that a client
* that supports timing marks also supports kludge linemode.
* A risky proposition at best.
* 2) Further negotiation of linemode is done by changing the
* the server's state regarding SGA. If server will SGA,
* then linemode is off, if server won't SGA, then linemode
* is on.
*/
void
localstat(void)
{
int need_will_echo = 0;
/*
* Check for changes to flow control if client supports it.
*/
flowstat();
/*
* Check linemode on/off state
*/
uselinemode = tty_linemode();
/*
* If alwayslinemode is on, and pty is changing to turn it off, then
* force linemode back on.
*/
if (alwayslinemode && linemode && !uselinemode) {
uselinemode = 1;
tty_setlinemode(uselinemode);
}
if (uselinemode) {
/*
* Check for state of BINARY options.
*
* We only need to do the binary dance if we are actually going
* to use linemode. As this confuses some telnet clients
* that don't support linemode, and doesn't gain us
* anything, we don't do it unless we're doing linemode.
* -Crh (henrich@msu.edu)
*/
if (tty_isbinaryin()) {
if (his_want_state_is_wont(TELOPT_BINARY))
send_do(TELOPT_BINARY, 1);
} else {
if (his_want_state_is_will(TELOPT_BINARY))
send_dont(TELOPT_BINARY, 1);
}
if (tty_isbinaryout()) {
if (my_want_state_is_wont(TELOPT_BINARY))
send_will(TELOPT_BINARY, 1);
} else {
if (my_want_state_is_will(TELOPT_BINARY))
send_wont(TELOPT_BINARY, 1);
}
}
#ifdef ENCRYPTION
/*
* If the terminal is not echoing, but editing is enabled,
* something like password input is going to happen, so
* if we the other side is not currently sending encrypted
* data, ask the other side to start encrypting.
*/
if (his_state_is_will(TELOPT_ENCRYPT)) {
static int enc_passwd = 0;
if (uselinemode && !tty_isecho() && tty_isediting()
&& (enc_passwd == 0) && !decrypt_input) {
encrypt_send_request_start();
enc_passwd = 1;
} else if (enc_passwd) {
encrypt_send_request_end();
enc_passwd = 0;
}
}
#endif /* ENCRYPTION */
/*
* Do echo mode handling as soon as we know what the
* linemode is going to be.
* If the pty has echo turned off, then tell the client that
* the server will echo. If echo is on, then the server
* will echo if in character mode, but in linemode the
* client should do local echoing. The state machine will
* not send anything if it is unnecessary, so don't worry
* about that here.
*
* If we need to send the WILL ECHO (because echo is off),
* then delay that until after we have changed the MODE.
* This way, when the user is turning off both editing
* and echo, the client will get editing turned off first.
* This keeps the client from going into encryption mode
* and then right back out if it is doing auto-encryption
* when passwords are being typed.
*/
if (uselinemode) {
if (tty_isecho())
send_wont(TELOPT_ECHO, 1);
else
need_will_echo = 1;
#ifdef KLUDGELINEMODE
if (lmodetype == KLUDGE_OK)
lmodetype = KLUDGE_LINEMODE;
#endif
}
/*
* If linemode is being turned off, send appropriate
* command and then we're all done.
*/
if (!uselinemode && linemode) {
# ifdef KLUDGELINEMODE
if (lmodetype == REAL_LINEMODE) {
# endif /* KLUDGELINEMODE */
send_dont(TELOPT_LINEMODE, 1);
# ifdef KLUDGELINEMODE
} else if (lmodetype == KLUDGE_LINEMODE)
send_will(TELOPT_SGA, 1);
# endif /* KLUDGELINEMODE */
send_will(TELOPT_ECHO, 1);
linemode = uselinemode;
goto done;
}
# ifdef KLUDGELINEMODE
/*
* If using real linemode check edit modes for possible later use.
* If we are in kludge linemode, do the SGA negotiation.
*/
if (lmodetype == REAL_LINEMODE) {
# endif /* KLUDGELINEMODE */
useeditmode = 0;
if (tty_isediting())
useeditmode |= MODE_EDIT;
if (tty_istrapsig())
useeditmode |= MODE_TRAPSIG;
if (tty_issofttab())
useeditmode |= MODE_SOFT_TAB;
if (tty_islitecho())
useeditmode |= MODE_LIT_ECHO;
# ifdef KLUDGELINEMODE
} else if (lmodetype == KLUDGE_LINEMODE) {
if (tty_isediting() && uselinemode)
send_wont(TELOPT_SGA, 1);
else
send_will(TELOPT_SGA, 1);
}
# endif /* KLUDGELINEMODE */
/*
* Negotiate linemode on if pty state has changed to turn it on.
* Send appropriate command and send along edit mode, then all done.
*/
if (uselinemode && !linemode) {
# ifdef KLUDGELINEMODE
if (lmodetype == KLUDGE_LINEMODE) {
send_wont(TELOPT_SGA, 1);
} else if (lmodetype == REAL_LINEMODE) {
# endif /* KLUDGELINEMODE */
send_do(TELOPT_LINEMODE, 1);
/* send along edit modes */
output_data("%c%c%c%c%c%c%c", IAC, SB,
TELOPT_LINEMODE, LM_MODE, useeditmode,
IAC, SE);
editmode = useeditmode;
# ifdef KLUDGELINEMODE
}
# endif /* KLUDGELINEMODE */
linemode = uselinemode;
goto done;
}
# ifdef KLUDGELINEMODE
/*
* None of what follows is of any value if not using
* real linemode.
*/
if (lmodetype < REAL_LINEMODE)
goto done;
# endif /* KLUDGELINEMODE */
if (linemode && his_state_is_will(TELOPT_LINEMODE)) {
/*
* If edit mode changed, send edit mode.
*/
if (useeditmode != editmode) {
/*
* Send along appropriate edit mode mask.
*/
output_data("%c%c%c%c%c%c%c", IAC, SB,
TELOPT_LINEMODE, LM_MODE, useeditmode,
IAC, SE);
editmode = useeditmode;
}
/*
* Check for changes to special characters in use.
*/
start_slc(0);
check_slc();
(void) end_slc(0);
}
done:
if (need_will_echo)
send_will(TELOPT_ECHO, 1);
/*
* Some things should be deferred until after the pty state has
* been set by the local process. Do those things that have been
* deferred now. This only happens once.
*/
if (_terminit == 0) {
_terminit = 1;
defer_terminit();
}
netflush();
set_termbuf();
return;
} /* end of localstat */
#endif /* LINEMODE */
/*
* flowstat
*
* Check for changes to flow control
*/
void
flowstat(void)
{
if (his_state_is_will(TELOPT_LFLOW)) {
if (tty_flowmode() != flowmode) {
flowmode = tty_flowmode();
output_data("%c%c%c%c%c%c",
IAC, SB, TELOPT_LFLOW,
flowmode ? LFLOW_ON : LFLOW_OFF,
IAC, SE);
}
if (tty_restartany() != restartany) {
restartany = tty_restartany();
output_data("%c%c%c%c%c%c",
IAC, SB, TELOPT_LFLOW,
restartany ? LFLOW_RESTART_ANY
: LFLOW_RESTART_XON,
IAC, SE);
}
}
}
/*
* clientstat
*
* Process linemode related requests from the client.
* Client can request a change to only one of linemode, editmode or slc's
* at a time, and if using kludge linemode, then only linemode may be
* affected.
*/
void
clientstat(int code, int parm1, int parm2)
{
/*
* Get a copy of terminal characteristics.
*/
init_termbuf();
/*
* Process request from client. code tells what it is.
*/
switch (code) {
#ifdef LINEMODE
case TELOPT_LINEMODE:
/*
* Don't do anything unless client is asking us to change
* modes.
*/
uselinemode = (parm1 == WILL);
if (uselinemode != linemode) {
# ifdef KLUDGELINEMODE
/*
* If using kludge linemode, make sure that
* we can do what the client asks.
* We can not turn off linemode if alwayslinemode
* and the ICANON bit is set.
*/
if (lmodetype == KLUDGE_LINEMODE) {
if (alwayslinemode && tty_isediting()) {
uselinemode = 1;
}
}
/*
* Quit now if we can't do it.
*/
if (uselinemode == linemode)
return;
/*
* If using real linemode and linemode is being
* turned on, send along the edit mode mask.
*/
if (lmodetype == REAL_LINEMODE && uselinemode)
# else /* KLUDGELINEMODE */
if (uselinemode)
# endif /* KLUDGELINEMODE */
{
useeditmode = 0;
if (tty_isediting())
useeditmode |= MODE_EDIT;
if (tty_istrapsig())
useeditmode |= MODE_TRAPSIG;
if (tty_issofttab())
useeditmode |= MODE_SOFT_TAB;
if (tty_islitecho())
useeditmode |= MODE_LIT_ECHO;
output_data("%c%c%c%c%c%c%c", IAC,
SB, TELOPT_LINEMODE, LM_MODE,
useeditmode, IAC, SE);
editmode = useeditmode;
}
tty_setlinemode(uselinemode);
linemode = uselinemode;
if (!linemode)
send_will(TELOPT_ECHO, 1);
}
break;
case LM_MODE:
{
int ack, changed;
/*
* Client has sent along a mode mask. If it agrees with
* what we are currently doing, ignore it; if not, it could
* be viewed as a request to change. Note that the server
* will change to the modes in an ack if it is different from
* what we currently have, but we will not ack the ack.
*/
useeditmode &= MODE_MASK;
ack = (useeditmode & MODE_ACK);
useeditmode &= ~MODE_ACK;
if ((changed = (useeditmode ^ editmode))) {
/*
* This check is for a timing problem. If the
* state of the tty has changed (due to the user
* application) we need to process that info
* before we write in the state contained in the
* ack!!! This gets out the new MODE request,
* and when the ack to that command comes back
* we'll set it and be in the right mode.
*/
if (ack)
localstat();
if (changed & MODE_EDIT)
tty_setedit(useeditmode & MODE_EDIT);
if (changed & MODE_TRAPSIG)
tty_setsig(useeditmode & MODE_TRAPSIG);
if (changed & MODE_SOFT_TAB)
tty_setsofttab(useeditmode & MODE_SOFT_TAB);
if (changed & MODE_LIT_ECHO)
tty_setlitecho(useeditmode & MODE_LIT_ECHO);
set_termbuf();
if (!ack) {
output_data("%c%c%c%c%c%c%c", IAC,
SB, TELOPT_LINEMODE, LM_MODE,
useeditmode|MODE_ACK,
IAC, SE);
}
editmode = useeditmode;
}
break;
} /* end of case LM_MODE */
#endif /* LINEMODE */
case TELOPT_NAWS:
#ifdef TIOCSWINSZ
{
struct winsize ws;
def_col = parm1;
def_row = parm2;
#ifdef LINEMODE
/*
* Defer changing window size until after terminal is
* initialized.
*/
if (terminit() == 0)
return;
#endif /* LINEMODE */
/*
* Change window size as requested by client.
*/
ws.ws_col = parm1;
ws.ws_row = parm2;
(void) ioctl(spty, TIOCSWINSZ, (char *)&ws);
}
#endif /* TIOCSWINSZ */
break;
case TELOPT_TSPEED:
{
def_tspeed = parm1;
def_rspeed = parm2;
#ifdef LINEMODE
/*
* Defer changing the terminal speed.
*/
if (terminit() == 0)
return;
#endif /* LINEMODE */
/*
* Change terminal speed as requested by client.
* We set the receive speed first, so that if we can't
* store separate receive and transmit speeds, the transmit
* speed will take precedence.
*/
tty_rspeed(parm2);
tty_tspeed(parm1);
set_termbuf();
break;
} /* end of case TELOPT_TSPEED */
default:
/* What? */
break;
} /* end of switch */
netflush();
} /* end of clientstat */
#ifdef LINEMODE
/*
* defer_terminit
*
* Some things should not be done until after the login process has started
* and all the pty modes are set to what they are supposed to be. This
* function is called when the pty state has been processed for the first time.
* It calls other functions that do things that were deferred in each module.
*/
void
defer_terminit(void)
{
/*
* local stuff that got deferred.
*/
if (def_tspeed != -1) {
clientstat(TELOPT_TSPEED, def_tspeed, def_rspeed);
def_tspeed = def_rspeed = 0;
}
#ifdef TIOCSWINSZ
if (def_col || def_row) {
struct winsize ws;
memset((char *)&ws, 0, sizeof(ws));
ws.ws_col = def_col;
ws.ws_row = def_row;
(void) ioctl(spty, TIOCSWINSZ, (char *)&ws);
}
#endif
/*
* The only other module that currently defers anything.
*/
deferslc();
} /* end of defer_terminit */
/*
* terminit
*
* Returns true if the pty state has been processed yet.
*/
int
terminit(void)
{
return(_terminit);
} /* end of terminit */
#endif /* LINEMODE */